Japan’s famous cherry blossoms reached their flowery peak in 2021 earlier than in any other time in at least 70 years of official record keeping, and scientists say climate change is the likely cause.
Peak bloom, called “sakura,” was reached on March 26 in the ancient capital of Kyoto, the earliest since 1409, according to less-official notes. The records from Kyoto go back to AD 812 in imperial court documents and other journals.
In Tokyo, full bloom was the earliest since the Japan Meteorological Agency started collecting the data in 1953 and 10 days ahead of the 30-year average. Similar records were set this year in more than a dozen cities across Japan.
The agency tracks 58 cherry trees around the country. This year, 40 of those trees already have reached their peak bloom; 14 did so in record time. The typical blooming period lasts two weeks.
“We can say it’s most likely because of the impact of the global warming,” said Shunji Anbe, an official at the observations division at the Japan Meteorological Agency, according to the Associated Press.
Scientists have tracked the Japanese cherry blossom 732 times since the year 821, according to seasonal records highly regarded in the country. In addition to cultural celebrations and tourism linked to the famous trees (including symbolism for the pandemic-delayed 2020 Olympics in Tokyo), farmers historically used the bloom to time the planting of rice crops.
According to the agency’s data, the average temperature for March in Kyoto has climbed to 10.6 degrees Celsius (51.1 F) in 2020 from 8.6 C (47.5 F) in 1953. So far this year’s average March temperature in Japan has been 12.4 C (54.3 F).
The meteorological agency and other scientists use cherry trees in overall climate-change research because of this species’ sensitivity to temperature changes.
“Evidence, like the timing of cherry blossoms, is one of the historical ‘proxy’ measurements that scientists look at to reconstruct past climate,” climate scientist Michael Mann told the Washington Post. “In this case, that ‘proxy’ is telling us something that quantitative, rigorous long-term climate reconstructions have already told us — that the human-caused warming of the planet we’re witnessing today is unprecedented going back millennia.”
Japan announced late last year it plans to achieve net zero carbon emissions by 2050, a date that matches promised timing in Europe and the United States.
The goal is part of an ambitious agenda for Prime Minister Yoshihide Suga as he works to wean his resource-scarce nation from its reliance on imports of oil
and gas. Progress toward reducing reliance on fossil fuels has also been hindered amid prolonged closures of most of Japan’s nuclear plants after the meltdown of the Fukushima Dai-Ichi plant due to the 2011 earthquake and tsunami.
About 40% of Japan’s carbon emissions come from power companies, and the nation must use more renewable sources of energy while stepping up development of technologies using hydrogen, ammonia and other carbon-free resources, experts suggest.
The Associated Press contributed to this report.